018 
THE EXCITO -MOTOR' Y NERVOUS SYSTEM OF 
The modus operandi of that divisional portion of the entire 
nervous system which Dr. Marshall Hall has designated the 
“ excito-motory,” will be best understood by keeping these esta- 
blished facts, concerning sensation and voluntary motion, imme- 
diately in view. This division of the nervous system, though dis- 
tributed to parts whose actions or functions are commonly carried 
on without our knowledge, and over which the will has little or no 
controul, still, like the voluntary system, appeared to require some 
stimulus of action, as well as some transmission of the state or 
condition the part to be acted upon was already in. A know- 
ledge of the state or condition of the part is conveyed to the com- 
mon nervous centre — the spinal marrow — by a nerve correspond- 
ing to the sentient, which is called an excitor, and from thence is 
reflected a motive influence along a distinct nerve, which is called 
a motor; the two sets of nerves running either together, as in the 
extremities, or going to their respective destinations apart from 
each other, and along with voluntary or sentient nerves, as in 
the thorax and head. 
The old division of the entire nervous system was into the 
cerebrospinal and ganglionic or sympathetic departments : to 
these Dr. M. Hall proposes to add a third, which, from its organic 
seat and uniform mode of action, he has designated the true spinal 
and excito-motory subdivision. His words on the subject are : — 
“ Viewing the cerebral or cerebro-spinal portion of the nervous 
system as the organic seat of mind — of sensation, perception, 
judgment and volition — and the ganglionic as that of the source 
of the movements of the internal muscular organs , of nutrition , 
secretion , &c. it has become obvious that there is an intermediate 
portion of this system, not formerly known ; viz. that of all the 
f unctions of ingestion and egestion , of exclusive retention, expul- 
sion, &c. This subdivision of the nervous system includes the 
respiratory system of Legallois and Sir C. Bell, under a new 
aspect. I have designated it, for the present, from its organic 
seat and the uniform mode of its action, the true spinal and 
excito-motory. The nervous system must, therefore, now be 
divided into — 
J. The Cerebral, or that of Sensation and Volition ; 
II. The True Spinal, or that of the movements of Ingestion 
and Egestion : and, 
III. The Ganglionic, or that of the movements of the Internal 
Muscular Organs, of Nutrition, Secretion, &c.” 
The following experiment of the doctor’s upon a frog will illus- 
trate what he means by excito-motory phenomena, as distinct 
from, and in a measure independent of, such as are properly 
cerebral : — 
